1. Field of Invention
The present invention relates to the field of information query, and particularly to an apparatus and method for expanding natural language query requirement.
2. Description of Prior Art
Currently, there are various systems for providing query results based on the query request transmitted by a user. In general, the user wants to obtain more information than the query request transmitted by him/her while conducting a natural language query. For example, when the user queries where the Hailong Building is, he/she may want to learn how to arrive at the Hailong Building in addition to its address. Therefore, it is desirable that the user's potential query requirement, i.e., implicit query requirement, can be inferred from his/her current query. On the other hand, the known query systems can only generate a direct query answer associated with the user's current query without giving further consideration to the user's potential query requirement for further expansion of the current query.
Some related query systems and methods have been proposed. US20050289124 provides a system and method for processing natural language query, which can process the English natural language query from a user, generate corresponding semantic label and retrieve corresponding information from a knowledge base.
U.S. Pat. No. 6,411,950 discloses an expanding method of keyword query, which utilizes a query log to expand an abstract word in the keyword query into a specific word having a high query frequency. As an example, the query word “car” is expanded as (“car audio” OR “rent a car” OR “car price” OR . . . ).
U.S. Pat. No. 6,480,843 also reveals an expanding method of keyword query, which expands the words in the keyword query by using semantic similarity between words. For example, “car dealer” in a keyword query can be expanded as [(“car” OR “automobile” OR “auto” OR “Ford”)] AND (“Dealer” OR “Showroom” OR “SalesOffice”).
In summary, the existing query systems and methods can either analyze an explicit query requirement as disclosed in US20050289124 or expand the words in the keyword query as recorded in U.S. Pat. Nos. 6,411,950 and 6,480,843. Therefore, there still exists a demand for a method which can effectively expand the current explicit query requirement in natural language query.